Subtract 81/70 from 70/40, Solve 1 30/40

Subtract 81/70 from 70/40

1^st number: 1 30/40, 2^nd number: 1 11/70

70/40 - 81/70 is 83/140.

Find the least common denominator or LCM of the two denominators:
LCM of 40 and 70 is 280

Next, find the equivalent fraction of both fractional numbers with denominator 280
For the 1st fraction, since 40 × 7 = 280,
70/40 = 70 × 7/40 × 7 = 490/280
Likewise, for the 2nd fraction, since 70 × 4 = 280,
81/70 = 81 × 4/70 × 4 = 324/280
Subtract the two like fractions:
490/280 - 324/280 = 490 - 324/280 = 166/280
After reducing the fraction, the answer is 83/140

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